Breadth first traversal of a tree

breadth_first_traversal.py

def bf_traversal(input):
    queue = []
    queue.append(0)  # Add root
    index = 0
    while len(queue) > 0 and index < len(queue):
        node = queue[index]
        print input[node],
        left = (index * 2) + 1
        right = (index * 2) + 2
        if left < len(input) and input[left] is not None:
            queue.append(left)
        if right < len(input) and input[right] is not None:
            queue.append(right)
        index +=1